Features: With excellent performance, it is suitable for robot, mechanical robotic arm, crawler and remote control toys. High torque, fast reaction to operation. With high precision, the metal gear has longer service life after hard anodizing. CNC machined middle shell enhances heat dissipation and ensure smooth operation of servo. Waterproof design ensures safe outdoor operation. Excellent choice for people who are interested in developing software for robot parts. It is tailored for RC lovers, offering different experiences and pleasures. Specification: Material: Plastic & Metal Color: Shown As Pictures Brand: DSSERVO Weight: 82 - 83g Type: Servos DSSERVO DS3218MG 20kg Torque Digital Servo Specification: Dead Band: 3s Voltage: 4.8 - 6.8V No-load Speed(5V): 0.16sec / 60 No-load Speed(6.8V): 0.14sec / 60 Stall Torque (5V): 19kg / cm (263.8oz / in) Stall Torque (6.8V): 21.5kg / cm (298.5oz / in) Motor Type: DC Motor Gear: Copper & Aluminum Working Frequency: 1520s/333hz CE Certification: Yes Size: Approx. 53 * 45 * 20mm / 2.09 * 1.77 * 0.79inch Package List: 1 x Servo 1 x Pack of Adjustable Metal Servo Arm 1 x Pack of Plastic Servo Arm Note: There is an error in the size of manual measurement, thank you for your understanding.